Interpretive Summary: As parasites become resistant to available anthelmintics, new methods of control are needed. New drugs take a long time to develop in addition to being expensive; therefore, there is increasing interest in finding and using natural alternatives. Additionally, natural remedies are needed for the organic sector as synthetic drugs are not allowed and birds with outdoor access are likely to encounter parasites. Sericea lespedeza [SL, Lespedeza cuneata (Dum. Cours.) G. Don.] is a common perennial legume found in pastures across the southern US that has been shown to be effective at controlling parasitic nematodes in small ruminants due to its condensed tannins content. Diets that are high in condensed tannins are often unpalatable to poultry; however, growers report that chickens maintained on pastures will consume SL. These reports and the level of consumption have not been verified. Therefore, before determining its potential in controlling parasites in poultry, a preliminary study confirmed that birds on pasture consumed SL (92% of birds examined had SL in crops), and in a subsequent study, dried SL leaves were added to a commercial broiler feed to determine the palatability of SL at various concentrations. Diets included 0% (Control), 5% (SL5), 10% (SL10) or 20% (SL20) SL (dry matter weight), and fed from hatch until harvest at six weeks of age. Male broilers (n=80) were randomly divided into eight groups and fed one of the four diets in replicate. Intake of feed was similar among treatments. Weight gains were similar between Control and SL at 5%. Including more than 5% SL in the diet reduced individual body weight (P<0.05). At the end of the feeding period, the digestive organs as a percent of body weight of SL20 birds were larger than Control birds. Feed conversion was higher in SL20 (2.31) than in Control (1.63; P < 0.05). Palatability of SL did not appear to be a problem as all treatment groups consumed a similar amount of feed. Therefore follow-up studies will evaluate the effects of SL on parasite control.

Technical Abstract:
As parasites become resistant to available anthelmintics, new methods of control are needed. New drugs take a long time to develop in addition to being expensive; therefore, there is increasing interest in finding and using natural alternatives. Additionally, natural remedies are needed for the organic sector as synthetic drugs are not allowed and birds with outdoor access are likely to encounter parasites. Sericea lespedeza [SL, Lespedeza cuneata (Dum. Cours.) G. Don.] is a common perennial legume found in pastures across the southern US that has been shown to be effective at controlling parasitic nematodes in small ruminants due to its condensed tannins content. Diets that are high in condensed tannins are often unpalatable to poultry; however, growers report that chickens maintained on pastures will consume SL. These reports and the level of consumption have not been verified. Therefore, before determining its potential in controlling parasites in poultry, a preliminary study confirmed that birds on pasture consumed SL (92% of birds examined had SL in crops), and in a subsequent study, dried SL leaves were added to a commercial broiler feed to determine the palatability of SL at various concentrations. Diets included 0% (Control), 5% (SL5), 10% (SL10) or 20% (SL20) SL (dry matter weight), and fed from hatch until harvest at six weeks of age. Male broilers (n=80) were randomly divided into eight groups and fed one of the four diets in replicate. Intake of feed was similar among treatments. Weight gains were similar between Control and SL at 5%. Including more than 5% SL in the diet reduced individual body weight (P<0.05). At the end of the feeding period, the digestive organs as a percent of body weight of SL20 birds were larger than Control birds. Feed conversion was higher in SL20 (2.31) than in Control (1.63; P < 0.05). Palatability of SL did not appear to be a problem as all treatment groups consumed a similar amount of feed. Therefore follow-up studies will evaluate the effects of SL on parasite control.